Exhaust-silencer for internal-combustion engines



W. H. MARTIN. EXHAUST SILENCER FOR INTERNAL COMBUSTION ENGINES.

' APPLICAT'IQ-N FILED NOV. 5, 1919.

1,342,340. Patented June 1, 1920.

,umrao .s T ss PATENT OFFICE.

"WILLIAM. HAMILTON lr'nnrru,

or "FLUfiHING, ETHER NDS.

EXHAUST-SILENGER romm'rnauaia-comniisrrou Emeritus.

"'Speifification of Letters hatent. Patented J 111143 1, i920,

Applicationfile l Iov'ember 5 1919. Serial No. 335,858.

To all whom it may concern: 1 I

Be it known that I, WILLIAM HAMILTON Mxn'mgs, a subject of the Queen of the Netherlands, residing at Flushing, Netherlands, have invented Improvements in Exhaust Silencers for Internal Combustion Engines, of which the following is ,a specification.

The usually employed types of exhaust silencers set up considerable back pressure and are therefore not used when the maximum power of an internal combustion engine is required, for instance in the case of an aeroplane engine.

Now the object of the present invention is to provide an exhaust silencer which,

while being capable of being made of light weight, will enable the noise of the exhaust to be very much reduced without involving the above mentioned disadvantage.

A silencer according to this invention comprises a chamber to which the exhaust gases are admitted through a light valve or valves of large area a single discharge nozzle from this chamber, and an unobstructed combining double cone surrounding the d1s-- charge nozzle and open at its rear to the atmosphere,.the -forward or discharge part of the cone extending with gradually 1ncreasing diameter for aconsiderable distance. The lift of the inlet valve to the chamber automatically adjusts itself to suit the volume of the gases beingexhauste'd and thereby maintains the velocity of the latter substantially constant. In the chamber referred to baffle plates are preferably ar-".

ranged so as to prevent direct flow from the' valved inlet to the discharge nozzle but they should be so arranged that the gases have ample room to pass them.

With such anarrangement the energy ot the exhaust gases is used up ejectorwise to put in motion a comparatively large quantity of air which acts to cool the gases, the combined stream of gas and air gradually expanding in the forward'part of the combining tube to substantially atmospheric pressure.

As will be understood theconstruction and arrangement may be variously modified. Thus in the case of an aeroplane engine only the parts mentioned would be employed and would be constructed of light material.

.The accompanying drawings illustrate such a silencer for an aeroplane engine,

' Figure 1 being a section and Fig. 2 an end view. In this'arrangement the silencer is applied to an exhaust manifold by pipe a fitted with alight valve 6 and opening in to a chamber" 0 the remote end of which isconed and formed with a discharge nozzle d. Surrounding the nozzle 03 is a combining double cone e the rear portion of which is enlarged as shown and provided with a curtain 6' between which and the wall of the chamber 0 air gains free access to the double cone e, and the fiontpor'tion is extended a considerable distance with gradually increasing area; in the example the larger end of the forward part ofthe cone is approximately of the same cross sectional area as the chamber 0!.

f, f are baflle plates so arranged as todiroot the gases through the chamber 0 alternately toward the wall and toward the-center as indicated by the arrows. g, g are wire sta s holding the silencer in position.

' he silencer of an aeroplane may be arranged horizontally and the exposed parts may, be of suchstream line formation as maiybe required.

n the case of a marine engine, the silencer might be arranged within the base of 'a funnel the top of which is provided with a series of annular louvers adapted to direct any water that may enter into a central ver- 'engine'roo'm by drawing warm air therefrom. I am aware that it has been proposed to construct an exhaust silencer comprising a compartmental casing containing bafliing. devices. and fitted with air admission openings, and to arrange between two of the compartments a dividing wall orpaz tition provided with a number of "tubes or nozzles for delivering exhaust gases from one com artment to the other the tubes or nozzles of the exhaust gases, and a flap valve eing adapted to retard back flow.

through which the exhaust gases are admitted, serving to prevent back flow of same. It has also been proposed to utiliz'e'the ex haust gases of internal combustion engines for inducing air currents through or over a radiator or the like by causing the said gases to flow through a nozzle into a chamber having converging sides and communieating with a shell or casing wholly or partially around the said cooling radiator or the like, and with a tube having diverging sides.

that I claim is 1. An exhaust silercer comprising a casing contracted at one end to form a sharply converging discharge nozzle, an unobstructed converging and diverging combining tube the converging portion whereof forms with the nozzle aforesaid an annular duct to which air has access uniformlyaround the casing, and valve means of large area at the end of the casing opposite to the nozzle adapted, to open automatically to an extent to suit the volume of gases being exhausted and thereby maintain the velocity of the latter substantially constant.

2. An exhaust silencer comprising a casing contracted at one end to form a sharply converging discharge nozzle, a gas inlet at the opposite end of the casing, a system of bafiies in the casing adapted to cause entering gases to pass alternately toward the wall and toward the center of the casing, and an unobstructed converging and diverging combining tube, the converging portion whereof forms with the nozzle aforesaid an annular ductto which air has access uniformly around the casing.

3. An exhaust silencer comprising a casing contracted at one end to form a sharply converging discharge nozzle, a gas inlet at the opposite end of the casing, a system of area at the gas inlet of the casing adapted to open automatically to an extent to suit the volume of gases being exhausted and thereby maintain the velocity of the latter substantially constant.

4. An exhaust silencer comprising a casing contracted at one end to form a sharply converging discharge nozzle,-a gas inlet at the opposite end of the casing, a system of bafiles in the casing adapted to cause entering gases to pass alternately toward the wall and toward the center of the casing, an unobstructed converging and diverging combining tube, the converging portion whereof forms with the nozzle aforesaid an annular duct to which air has access uniformly around the casing and a gravity closing lift valve of large area at the gas inlet of the casing adapted to open automatically to an extent to suit the volume of gases being exhausted andthereby maintain the velocity of the latter substantially constant.

Signed at London, England, this 17th day of October, 1919.

WILLIAM HAMILTON MARTIN. 

